Do your research! There is a lot of information about there about sleep training, and much of it is controversial or contradicting. However, just like making any important decision, your choice to sleep train (or not sleep train) should be informed by your own reading, research, and inferences. Furthermore, there are many different methods of sleep training (which we’ll cover in this article as well) and you’ll need to decide which method is right for you.
"No Tears" Techniques: Just as some parents and experts believe that it is harmless to allow an older baby to cry for set periods of time, others prefer sleep-training methods that gradually teach the baby to fall asleep without Mom or Dad’s help. For example, one "no tears" method involves sitting in a chair next to the crib while the baby falls asleep, and then, each night, moving the chair farther from the crib until it's in the doorway—and then, finally, outside the room.
There are various schools of thought on sleep training. Some sleep-training methods fall under the umbrella of “gentle sleep training,” which generally means you’re still going to pick up, rock and soothe baby if she cries. Other methods, often under the “extinction” label, advise parents to let baby self-soothe for the entire night and not open the door until morning. Neither of these methods are right or wrong—it all depends on what works best for you and your family.
It’s okay if you’re not ready. You aren’t missing out on sleep training if you skip it at 4 months: You truly can start sleep training at any age, even in the toddler years, although experts say it’s smart to be aware of developmental milestones and adjust baby’s sleep schedule accordingly. For example, the week baby learns to walk may be tough to implement a sleep-training schedule, and even a sleep-trained baby may see a regression simply because he’s going through such a developmental shift.
The age of your baby might determine what kind of sleep-training method you choose, though. You could try a gentle shush-pat technique with a five-month-old, but you’ll likely have to leave a one-year-old in the crib as they protest (cry or scream) about the new bedtime arrangement. Don’t attempt a formal sleep-training method before four months, until your baby is able to go longer in between feeds and their circadian rhythm starts to develop. (Many babies this age still feed in the night—contrary to popular thinking, sleep training isn’t synonymous with night weaning.) Dickinson says that many four-month-old babies are biologically able to go through the night without a feed, but that doesn’t mean you shouldn’t respond and feed them if other methods of calming them aren’t working. Since every situation is different, we recommend checking with your doctor before withholding your baby’s night-time feeds.